Coils, once made at the end of the production process or treatment, have a packaging problem. Indeed, coils, generally consisting of rolls of steel, aluminium alloy or steel alloy sheet, are of a large size (diameter of up to 2 m, width of up to 2 m) and are heavy (from 15 to 27 tons).

Upon the basis of the sizes mentioned above it is easy to understand how it might be difficult to package them. Moreover, the packaging of coils is necessary both for the movement thereof inside the factory and for the subsequent transportation and storage, to avoid damage which can harm the value of the product.

Indeed, the rolls of sheet or coils generally derive from painting or electrozinking treatment lines or other surface treatment lines which make coils a product with a higher added value, but which are subject to deterioration due to surface knocks or due to oxidation, which is particularly noticeable during transportation by sea or when it is stored in a warehouse where there is moisture and heat variations.

Numerous packaging systems made of various materials (paper, metal crate, circumferential and radial

bundling, etc.) which, moreover, do not allow the products to be preserved in an optimal manner are known. Moreover, it must be noted that these known systems have high costs and numerous other drawbacks connected to the dangerousness of the packaging operations and to the difficulty in disposing of the materials used.

More specifically, the problem of packaging coils is currently dealt with mainly according to the two procedures which are briefly considered hereafter.

A first procedure uses a paper packaging. The packaging material is made up of a sheet of oleate plasticised paper coupled with a nylon filling. The packaging operations foresee the positioning, through an overhead-travelling crane, of the coil on the previously cut sheet, the subsequent manual winding and folding and the encasing with metal"bundles".

A second packaging procedure foresees the use of a metallic crate. In particular, besides the paper, a sheet of 0.6 mm thick sheet steel is used which is cut and folded manually on the outer part of the coil, is fixed to two side covers, also made of sheet steel and cut and folded manually. This second method is the most commonly used one, particularly in cases in which it is necessary to guarantee a greater protection of the product.

It is clear to see what are the problems connected with the quoted known systems.

A first problem is connected to the material used (paper, sheet metal, etc.) which is not easy to dispose of and also is costly to recycle.

Moreover, it is necessary to have a large workforce, due to the totally manual nature of the operations for positioning the side covers, the circumferential and radial bundling, and of other packaging steps.

Consequently, this results in a low productivity even when there is a large team of operators.

The complicated nature of such known systems, moreover, requiring operators to be present, carries a high risk of accidents in the workplace. Indeed, the cutting, positioning and fixing operation of the large, thin and sharp sheet of steel is often the source of accidents.

Also the unpacking step is very dangerous since the outer sheet must be held until it is completely unrolled.

It should not be forgotten that, in spite of such a complex, expensive and dangerous work, a low quality packaging is created. Indeed, the systems currently used are not capable of guaranteeing that the product be protected from oxidation, which can cause serious losses to the value of the coil. In the case of paper packaging, there is also a serious risk of deformation

due to surface knocks during transportation.

As already stated, there are problems for packaging which, once used, are no longer reusable and are difficult to dispose of, due to their varied composition of paper, plastic, steel, etc.

The purpose of the present invention is, therefore, that of making a packaging unit for coils which is capable of avoiding all of the technical problems and the drawbacks listed above.

A further specific purpose of the present invention is that of making an efficient automation of every step of the packaging procedure, in such a way increasing productivity, reducing the risk of accidents and guaranteeing an absolute protection of the coil from knocks and from atmospheric agents.

Another purpose of the present invention is that of making the materials used for packaging totally recyclable, avoiding disposal problems.

These purposes according to the present invention are achieved by constructing a packaging unit for coils according to claim 1.

The characteristics and advantages of a packaging unit for coils according to the present invention will become clearer from the following description, given as an example and not for limiting purposes, referring to the attached schematised drawings in which:

figure 1 is a plan view from above of a unit according to the present invention, showing various steps of its operation, figure 2 is a plan view from above of the unit of figure 1 in a first work step, figures 3-8 are plan views of the successive steps up to the evacuation of the packaged coil according to the invention, figures 9-10 show enlarged schematic section views of an extruder in the deposition step of the continuous sheet on the outer surface of the coil which is carried by a cradle, and figures 11-12 show enlarged schematised section views of an extruder in the deposition step of the continuous sheet in the inner surface of the coil.

With reference to fig. 1 a plan view from above of a coil realised according to the present invention is illustrated in which the individual devices and groups which comprise them are schematised.

The unit comprises a feeding transporter 11 on which individual coils 12 are arranged to be put in a packaging position illustrated with 13 near to the end of the transporter itself 11 arranged on a motorised cradle with rollers 10. Before the coil 12 to be packaged is put into such a position, a size detector 14 is foreseen which detects the maximum size of the

coil 12 both in terms of its width and diameter, as well as the size of its inner hole, sending such sizes to a central computer 15. A control panel of such a central computer 15 takes care of controlling the functions of the various devices and groups of the unit.

In such a packaging position 13 a group of apparatuses which carry out the treatment of a single coil 12 is arranged. This is done so as to obtain its packaging in a material which is easy to recycle and to heat solder, for example consisting of a film of monocomponent material or plastic material in general, such as high density polythene.

Firstly a manipulator 36 of sheets 16 of polythene is foreseen, such sheets being of a greater size than the maximum diameter of the coil and being arranged in a stack. The manipulator 36 takes care of clasping a single sheet 16 and of the displacement thereof at a support plate 17 associated with a cutting apparatus 18.

This apparatus 18, for example an apparatus for laser cutting, milling cutting, water pressure cutting, etc., has an arm 19 which can be displaced in the horizontal plane above the sheet 16 arranged on the support plate 17. The arm 19 carries a cutting element 20 which, through the command received from the computer 15 upon

the basis of the measurements detected by the detector 14, takes care of cutting out a flat ring 21 from the sheet 16.

Each flat ring 21 is then clasped by a further two manipulators 22 which arrange it on bases or heads 23 opposite the coil 12. Regarding this, it is obvious that once a first flat ring 21 is made, it is clasped by a first manipulator 22 and is arranged at a first head 23 of the coil. At the same time the cutting apparatus 18 takes care of the preparation of the second flat ring 21 which must be arranged through the second manipulator 22 on the other head 23.

The support surface 17, upon which rests a trimming 24 of a sheet 16 from which the flat ring 21 was formed, can foresee a pair of transporters 25 which take care of removing the trimmings 24 which form during the cutting operations.

Once the two manipulators 22 have arranged the flat rings 21 at the heads 23 of the coils 12 being packaged, the intervention of a flat-headed extruder 26 is foreseen, arranged so as to be capable of sliding on a base block 27.

The extruder 26, for example of the single-screw type, is arranged on a sled 28 capable of sliding on the base block 27, so as to be capable of being moved between a position next to the packaged coil 12 and a position

either inserted in a central hole 29 of the coil 12 or superposed on the side surface of the coil itself, as shown in figures 6 and 7 and 9-12. For such a purpose each manipulator 22 foresees a central hole 30 in its clasping head 31 to allow the passage of an extruder head 32 making up part of the extruder 26. The extruder head 32 has a reduceable nozzle, so that it is possible to vary the width of the continuous sheet according to the width of the coil being packaged.

Once the extruder 26 has taken care of arranging a continuous sheet 33, having a greater width than that of the coil 12, deviator and folding elements 34 intervene, associated for example with the extruder head 32, which act upon the edges of the continuous sheet 33 folding them over above each flat ring 21. As soon as the sheet material has been extruded, it is soldered by contact and pressing.

Figures 9 and 10 show how the direct extrusion operation of the continuous sheet on the outer side surface of the coil takes place and how the folding elements 34, in the form of rollers, act on the edge of the flat sheet. It should, indeed, be noted how the flat sheet is folded over on each of the two flat rings 21, straight after being extruded on the surface of the coil.

Figures 11 and 12 show in an equivalent manner how the

deposition of the continuous sheet inside the hole 29 of the coil takes place with the identical intervention of the folding elements 34, in the form of rollers, on the edge of the flat sheet, so as to make it integral with the central hole of each of the flat rings 21.

At this point the coil 12 is perfectly packaged, is discharged from the rotating bracket 10 and is evacuated by an evacuation transporter 35, ready to be sent on or to be stored away in a warehouse.

Therefore, the advantages of the present invention are clear, allowing all manual interventions to be eliminated and avoiding the use of bundling devices, with a saving of time and resources.

Moreover, it should be noted how the packaging material can be easily removed from the coil and can be recycled without any problem.

The central computer 15 allows the activation, thanks to the detection carried out upstream of the coil being packaged, of all of the connected devices, automatically making the size choices relative to the cutting and the extrusion.

According to the present invention one can thus obtain a coil packaged in polythene or a similar material which is capable of maintaining its integrity for a long time and also when put under various stresses.

With a unit of the invention and with a procedure

according to what has previously been revealed it is possible to obtain a series of notable advantages.

As well as the high protection of the coil against atmospheric agents and in general against the environment, a high productivity is obtained with an extremely limited number of personnel. This is the case since, as we have seen, the unit is completely automated and only requires one operator at the control panel.

Furthermore, a high quality packaging having a certain robustness is obtained with a low-cost material.

Moreover, this monocomponent material, used both as a support inside the coil and as an outer casing, is easily available and is environmentally friendly since it is easy to recycle.

Advantageously, the type of material is such as to prevent injury and accidents both to the personnel employed to work with the unit and to the personnel which will subsequently have to manipulate the packaged coil once it has been received. The removal of the protective material is extremely simple and easy and elements to make it even easier can be foreseen.